SWITCHGRASS AS AN ALTERNATE FEEDSTOCK FOR POWER GENERATION: INTEGRATED ENVIRONMENTAL, ENERGY, AND ECONOMIC LIFE-CYCLE ASSESSMENT

摘要

Biomass conversion into forms of energy is receiving current attention because of environmental, energy supply and agricultural concerns. This paper reports on a environmental biocomplexity based analysis of the environmental, energy, economic, and technological aspects of using one form of biomass - switchgrass (panicum virgatum) as a replacement for coal in power generation. The main questions regarding such a substitution pertain to the cost, environmental impact, and net balance of greenhouse gases. This paper summarizes the results of an investigation into these questions using an environmental biocomplexity approach that addresses agricultural, technological, economic, and environmental factors along with their interaction. In particular, this paper attempts to:rnProvide an economic, energy and environmental evaluation of the prospects for switchgrass as a bioenergy feedstock into electricity generation using lifecycle analysis.rnDevelop an environmental biocompiexity, lifecycle-based approach that permits identification of most effective technological enhancement possibilities and alternative material handling procedures.rnExamine how potential GHG emission pricing alternatives might influence the relative efficiencies of alternative technologies and other strategies as well as the power generation market penetration of biomass.rnImplement a framework that permits additional evaluations to be done in the future.rnExamine the sensitivity of the findings in the face of a wide spectrum of possibilities for switchgrass production, preparation and delivery as well as the degree of desirable co-firing of power plants.rnThe analysis shows that the most effective technologies for switchgrass preparation are harvesting loose material for hauling and chopping then compressing it into modules and transporting. The greenhouse gas (GHG) mitigation is found to be substantial with the mitigation contribution under co-firing found to be greater per ton of switchgrass than for switchgrass fired alone. This paper also analyzes the implications of switchgrass use under alternative co-firing ratios, coal prices, hauling distances, and per acre yields.